only Athlon XP's had a BSB that I know of.
It is the link between L2-Cache and CPU.
on newer CPU's the L2-Cache is On-Die, so they don't need one.
the FSB is the link between CPU and memory controller, and the memory controller talks to RAM.
on AMd K8 CPU's, the memory controller is on the CPU itself, so the FSB is inside the CPU.
the 1000MHZ bus you are referring to is the HTT, the link between CPU and RAM. this isn't used on any other processor, except for the IBM PowerPC 5, in the Macintosh G5
to determine CPU speed, AMD uses a P-rating, because clock speeds don't tell you the CPU's performance. the architectures between different CPU's is different. the AMD Athlon CPU's process instructions in a fewer amount of clock cycles than Pentium 4's.
the P-rating is the number in the CPU name, like 3200+